A conventional way to move a heavy object such as a bed, a desk or a piece of furniture is to connect multiple wheels at the underside of the object so as to easily move the object. The wheels can move in one direction and cannot turn. The casters are then developed which are able to turn so that the casters provide more convenient functions to the users. Nevertheless, the casters will move when the object is located on an inclined surface and may cause damage to the object. Therefore, a brake unit is installed to the caster so as to brake to prevent moving on an inclined surface. Some casters further have a direction unit which controls the casters to move in the desired direction.
The conventional casters may include one wheel or two wheels, the brake unit for one-wheel caster can direct touch the wheel to brake it. The two-wheel caster includes an inner gear cooperated with a brake lever to be engage with the inner gear to stop the casters.
As shown in FIGS. 6 and 7, the conventional casters with brake unit and direction unit generally include a brake lever 52 and a direction lever 51 which is located side-by-side to the brake lever 52. Both of the brake lever 52 and the direction lever 51 are controlled by an operation unit to selectively operate either of the brake lever 52 or the direction lever 51. The side-by-side brake lever 52 and the direction lever 51 are located so close and look alike so that the user often to operate on the wrong lever.
The present invention intends to provide a caster which has a brake unit and a direction unit, and the two units can be operated by two respective levers so that the user can correctly operate the caster.